Relational Table : Relational Tables

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Relational Tables:
The relation between numbers of tables in a database is called Relational tables.
By using relational tables we can perform join operations on database tables and get optimized results which are required.
Relational tables solve the joining of table’s problem by verifying the combination of primary and foreign key in the tables being joined.
I used these relational tables in assignments like working with chinook database, where the queries are written for optimizing various results by joining tables.
Joining of tables in SQL Databases we generally use these concepts. Data Retrieval form database by comparing different tables these concept is very helpful.
These concept goes down where the joining is applied on very large
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Using of Index values where the size of database increases for storing these values separately and separate handling should be there for these values when alter to a data occurs.
Altering of data may be update, delete or change of the complete structure of table.
Covering Index:
A Covering Index contains possibly more, the columns you need for your query to perform faster.
A covering index is that which contains all the data needed for a query and original table is never needed to be consulted.
Covering index solve the problem of more tables in database and query search delays.
These is achieved by creating a covering index, where tables are combined into one with common in between both and the new column is also given as index value.
These concept I used when performing assignments of TODO.
Good for reducing the size of Database that is optimization by reduction. Also bad thing is creation of another table for maintaining these index values.
Foreign Key: Foreign key is a constraint that is used to enforce exists relationship between tables.
These Foreign key is enforced on a table while creation itself where it simplify that it is creating an connection between two tables as its importing the data properties.
Foreign key constraint has an exception if the table in which the key is primarily defined is NULL then the table corresponding to it should have entry.
We used these concept in very
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